Are you weary? Don't give up:

Hast thou not known? hast thou not heard, that the everlasting God, the Lord, the Creator of the ends of the earth, fainteth not, neither is weary? there is no searching of his understanding. He   giveth power to the faint; and to them that have no might he increaseth strength. Even the youths shall faint and be weary, and the young men shall utterly fall: But they that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be        weary; and they shall walk, and not faint. (Isaiah 40:28-31

And let us not be weary in well doing: for in due season we shall reap, if we faint not. (Galatians 6:9)

Come unto me, all ye that labor and are heavy laden, and I will give you rest. Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls. For my yoke is easy, and my burden is light. (Matthew 11:28-30) 

Are you in a battle? Don't give up:

Finally, my brethren, be strong in the Lord, and in the power of his might. Put on the whole armor of God, that ye may be able to stand against the wiles of the devil. For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. Wherefore take unto you the whole armor of God, that ye may be able to withstand in the evil day, and having done all, to stand. (Ephesians 6:10-13) 

Are you grieving? Don't give up: 

My soul melteth for heaviness: strengthen thou me according unto thy word. (Psalm 119:28)

The sorrows of death compassed me, and the pains of hell gat hold upon me: I found trouble and sorrow. Then called I upon the name of the Lord; O Lord, I beseech thee, deliver my soul. Gracious is the Lord, and righteous; yea, our God is merciful. The Lord preserveth the simple: I was brought low, and he helped me. Return unto thy rest, O my soul; for the Lord hath dealt bountifully with thee. (Psalm 116:3-7) 

O Lord my God, I cried unto thee, and thou hast healed me. O Lord, thou hast brought up my soul from the grave: thou hast kept me alive, that I should not go down to the pit. Sing unto the Lord, O ye saints of his, and give thanks at the remembrance of his holiness. For his anger endureth but a moment; in his favor is life: weeping may endure for a night, but joy cometh in the morning. (Psalm 30:2-5) 

Are you being scoffed at? Don't give up:  

For the Lord God will help me; therefore shall I not be confounded: therefore have I set my facelike a flint, and I know that I shall not be ashamed. He is near that justifieth me; who will contend with me? let us stand together: who is mine adversary? let him come near to me. Behold, the Lord God will help me; who is he that shall condemn me? lo, they all shall wax old as a garment; the moth shall eat them up. Who is among you that feareth the Lord , that obeyeth the voice of his servant, that walketh in darkness, and hath no light? let him trust in the name of the Lord, and stay upon his God. (Isaiah 50:7-10) 

Do you feel there is no hope? Don't give up:

Why art thou cast down, O my soul? and why art thou disquieted in me? hope thou in God: for I shall yet praise him for the help of his countenance. (Psalm 42:5) 

Are finances burdening you? Don't give up:

But godliness with contentment is great gain. For we brought nothing into this world, and it is certain we can carry nothing out. And having food and raiment let us be therewith content. (1 Timothy 6:6-8)

Therefore I say unto you, Take no thought for your life, what ye shall eat, or what ye shall drink;   nor yet for your body, what ye shall put on. Is not the life more than meat, and the body than raiment? . . . Wherefore, if God so clothe the grass of the field, which today is, and tomorrow is    cast into the oven, shall he not much more clothe you, O ye of little faith? Therefore take no thought, saying, What shall we eat? or, What shall we drink? or, Wherewithal shall we be clothed? . . . for  your heavenly Father knoweth that ye have need of all these things. But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you. (Matthew 6:25-33)